Many devices have been developed for felling trees. Some of these devices have been incorporated into self propelled mechanisms by mounting the felling head on a vehicle. The one thing all of the machines have in common is that a mechanism is provided to sever the tree from its base. Large shears, reciprocating saw blades, various configurations of chain saw blades and circular saws all have been used with some success.
Generally the devices which use circular saws have a guard or housing about the circular saw blade to protect the operator and other personnel from the saw blade. An opening is usually provided in the front portion of the guard to expose a portion of the saw blade for cutting the tree. This arrangement, however, limits the diameter of the tree which can be cut. One method to cut oversize trees was to partially cut the front side of a tree, drive the felling apparatus to the back of the tree and complete the severing from the backside of the tree. This method is time consuming and often is not practical because of the density of most woodlots.
Kurelek, U.S. Pat. No. 4,446,897, recognized the mobility problem and mounted the circular saw and felling head on a boom which is attached to a vehicle. Kurelek also placed a second opening in the saw guard to allow the saw blade to cut on either side. The Kurelek apparatus was thus able to cut in a straight ahead mode or in a side-swing or scything mode. Although an improvement over the prior art the Kurelek patent has the disadvantage of leaving the second portion of the saw blade exposed and unprotected. Kurelek also does not address the problem of felling an oversize tree.
The present invention thus overcomes the limitations and problems in the prior art.